Bug in .variety() of zero dimensional ideal over QQ

[Georgi Guninski]

I got linear zero dimensional ideal in 48 variables over QQ and when I
run .variety() I get error and traceback. Looks like the python
exception isn't caught due to a deeper error. Groebner basis of the
ideal works.

For most ideals, variety works.

Tested on 10.6 on linux

From the attached testcase:

print("dimension=",Ideal(J).dimension()) # returns 0
try:
va=Ideal(J).variety()
print(" variety passed")
except Exception as e:
print(" exception in variety ",e) #error skipping text from `)`
error at token `)` and traceback

[Vincent Delecroix]

Works for me (archlinux system sage (version 10.6))

sage: va=Ideal(J).variety()
sage: va
[{x47: 697230/5107,
x46: -3963219/20428,
x45: 877339/5107,
x44: -255117/20428,
x43: -1366305/10214,
x42: -1153515/5107,
x41: 144,
x40: 121,
x39: 1439210/15321,
x38: -2717419/20428,
x37: 602811/5107,
x36: -582751/61284,
x35: -2869931/30642,
x34: -2327701/15321,
x33: 100,
x32: 81,
x31: 908570/15321,
x30: -1706491/20428,
x29: 379747/5107,
x28: -421039/61284,
x27: -1858763/30642,
x26: -1418953/15321,
x25: 64,
x24: 49,
x23: 166590/5107,
x22: -930435/20428,
x21: 208147/5107,
x20: -93405/20428,
x19: -355137/10214,
x18: -244767/5107,
x17: 36,
x16: 25,
x15: 212810/15321,
x14: -389251/20428,
x13: 88011/5107,
x12: -160279/61284,
x11: -489875/30642,
x10: -273745/15321,
x9: 16,
x8: 9,
x7: 47690/15321,
x6: -82939/20428,
x5: 19339/5107,
x4: -61231/61284,
x3: -132155/30642,
x2: -37285/15321,
x1: 4,
x0: 1}]

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[Georgi Guninski]

On Tue, May 20, 2025 at 2:48 PM Vincent Delecroix

<20100.d...@gmail.com> wrote:
>
> Works for me (archlinux system sage (version 10.6))
>
> sage: va=Ideal(J).variety()

Thanks for testing.
I think the problem if any is in Singular.
My Singular is:
Singular for x86_64-Linux version 4.4.0 (44004, 64 bit) Aug 19 2024 00:00:00

The problem is present on sagecell:

https://sagecell.sagemath.org/?z=eJxNlk9v2zYYh8814O9AuIcmnl2I5CuRDJDDBgzFusu66zCsaqJmWhw5kJXC6acf379uLhQk85H0e8KfuNls1qtfXh7cOLlv_TwOy6s7fnXfh_no7senYTot43HqD268H_rDevXzy_Lvcb5xH4bj_DC6Dy_TOJ0eRxea0O6bdh-a9WqDzN_Pt38cD6_T8WnsD3-O08PVp0-7d-d3O8jXePX9OP033C3_4E37L4fhdFVPr1cfb_8K23PjfnJxe_Z1aLfnUIe0Pcc6eL89A471aotjPd_hWLbntHN1auaphaf6hud6L5N9kNk-ynQPMt-3BPCd3DwJIguiCCI0ggheECEIIkRCBGBEaOUFOkaEpIisiCKI2AgiekLEwIgYGRFBQmgFETtBxKSIrIhCCJAUQWIEyREsSE0SNErQLAHDjCwiFDYRPauI4gLEBYgLEBdtZBeRZeD0ItNJR1QfoD5AfYD6QAb5iCKEHiIpJiumCIacgDoBdYIYchJFCmLICr1MJxjyAuoF1AuoF8SQlyhiEENmEENqoroBdQPqBtQNYQpjQJMFjRY0W7BwNV3QeEHzRT9tYT-dZz9dkqXi2U-K7CcV9pMj-8m8VnB6lulFpvNy8eIHAeQHCeQHEeQny3pBCPmhh0iKyYopgiE_iCE_iCE_WdYMYsgPYsgPvUwnGPJDmKyYIhjyk2XdIIb8IIb8IIaXjhc_iCE_iCE_hMmKKYwBTRY0WtBswcLVdEHjBc0X_ZTEfnwjgnwT2ZBvtM6aIn1mhRa00fB_QihZKUUpvlEMNxtyuNou3Ras3GjNtMwiW_xIyWjZaEVp3HKXmgvWc7R0ItNIGtHIGr9hpzTuO6JloxWlceXRCvJMi0FpMSotggXWKo2771J-wdqPaIVpYOGDpQ8WP1zyNwFgBsAUoEkfVWWULvRQRGUrq823SVR2qrJTlYkbkTBZMUUx7LLVVUcgdtmZy85cJmlGgrHMqN3IuGy4ojiW2ZnMzmQmaUjCsc2oHckv2SmObRIuG64ojm0maUrCsc6oXUk41tnqaiQc6-xMZ2c6kzQm4cAMgCkAcwAXCWYBTAOYB_KZpDp91qVZ5OPmSxSfRX0W6c-A30z6FgXxmaRCCVMUwz6Rwz6L-Szao4Qin8Qin0mrlB8qGS4briiOfRbtU8KRT8KRz6SVSjj2WfSjRzj2Wcxn0V4lHPkkHPlMWq2EY59FP34cWqs49lm0XxmXDVcEB2YATAGYA7hIMAtgGsA8oM_qcu_qU1aVewd1zHWst6lO6vkOL3T1KLR4lOpRxHM1nfpr_FlNZ-86nFhfce8youor1rlNUw-B8AHPAt7BA_yNe9X16u2t_a1Xz_M4LVcb3jXXTfPtZvcbbpqvPl6_t5NX19furZuH5WWeTq5ulpf59Wa9evOtv7Ufyz4cN8RvBGp78-f-dBruN_XScL4bnhf3Kw2V7PqTG25-mDLYlR_29pvdUB9gmOfj7Oq-_fm57szdMpwX93U-PrnP158dX-wXtxwfh4lO9dO9W-b-bvjS3z3-D0Aosnc=&lang=sage&interacts=eJyLjgUAARUAuQ==

[Vincent Delecroix]

My version is just a little bit ahead

Singular for x86_64-Linux version 4.4.1 (44100, 64 bit) Jan 2025

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